Applicant's co-pending Canadian Patent Application Serial No. 2,273,522 proposes a technique of mapping high speed (HS) Ethernet frames (e.g. originating in a local area network [LAN] using a fiber distributed data interface [FDDI] physical layer) into a synchronous container (e.g. thin synchronous optical network [SONET] STS-192C or synchronous digital hierarchy [SDH] VC-4-64C frames) for transport across a synchronous packet switched network fabric at a standard OC-192 line rate of 9.95328 Gbaud, to achieve a data rate of 9.5864 Gb/s. This data rate is obtained independently of the LAN/MAN/WAN configuration of the network. The use of standard line rates in all configurations means that a common physical medium dependent (PMD) interface can be used, which reduces costs by permitting increased economies of scale. Additionally, conventional SONET/SDH routing systems (e.g. routers, cross-connects and add-drop multiplexors) can be used to transport data traffic in all configurations. Despite its versatility, the technique of Canadian Patent Application Serial No. 2,273,522 is unattractive for use in LAN configurations, because HS Ethernet LANs commonly provide a data rate of 10 Gb/s. As a result, implementation of this technique in LAN configurations would have the effect of degrading overall data performance.
An alternative protocol has recently been proposed for mapping HS Ethernet frames into synchronous containers, that is intended to achieve a data rate of 10 Gb/s for LAN configurations. However, in order to obtain this data rate, the synchronous container must be transmitted at an accelerated line rate of 10.3125 Gbaud. This non-standard line rate means that conventional SONET/SDH routing systems cannot readily be used in LAN configurations. Furthermore, the use of an accelerated line rate reduces data transmission reliability. According to this proposal, the standard OC-192 line rate of 9.95328 Gbaud is used for WAN configurations. However, the use of different line rates for LAN and WAN configurations means that respective different PMD interface devices must be used for each configuration. This latter requirement increases costs by reducing economies of scale.
Accordingly, a method and apparatus of mapping high-speed (HS) Ethernet signals to a synchronous container for transport across a synchronous packet-switched network fabric, which enables an Ethernet data rate of 10 Gb/s in LAN configurations of the network, while using a standard OC-192 line rate of 9.95328 Gbaud, remains highly desirable.